Direct Inguinal Hernia
In contrast to the indirect hernia, a direct hernia is most
often an acquired lesion. It occurs when a weak spot develops in the lower
abdominal musculature (the posterior floor of the inguinal canal) due to the
normal and/or abnormal stresses inflicted by living and aging. In adults,
stresses such as lifting heavy of objects, frequent coughing or straining,
pregnancy, and constipation can instigate hernia.
Unlike indirect hernias, direct hernias traverse medial to
the inferior epigastric vessels and are not associated with the processus
vaginalis. The hernia consists primarily of retroperitoneal fat. Only rarely
is a peritoneal sac containing bowel encountered. Because there is typically no
involvement of a sac, they do not protrude with the spermatic cord, and as such,
have a lower incidence of incarceration or strangulation.
Probably the largest single risk factor for developing an inguinal hernia is
being male. Men are almost 10 times more likely to develop an inguinal
hernia than females. Other factors (which mainly lead to an increased
pressure in the lower abdomen) put the general population at risk. They
|Family History: There is an
increased risk of hernia with a close family history|
|Certain Medical Conditions:
Cystic fibrosis, or conditions associated with a chronic cough
increase the risk of developing a hernia|
|Smoking: Like cystic
fibrosis, a chronic cough increases risk|
Excessive straining over time can lead to hernia|
|Excess Weight & Pregnancy:
Increases risk by weakening and placing stress on lower abdominal muscles|
|Past History: Having one
hernia puts you at risk of having another|
Like indirect inguinal hernia, direct inguinal hernias typically cause a bulge in the groin (at the top of
or within the scrotum) and usually with increased abdominal pressure. Like
indirect hernias, they may or may not be painful (usually not). By
palpating the inguinal canal and asking the patient to cough while standing, one can usually
elicit the hernia. In fact, one can often times palpate an inguinal hernia
without invaginating the scrotum (as is typically taught in medical school).
Rather, by placing one's fingers over the inguinal canal and asking the patient
to cough, one can often feel the bulge against the lower abdominal wall.
As direct and indirect hernias are unreliably differentiated by physical exam
alone, the need to invaginate the scrotum to feel into the inguinal canal is
often more uncomfortable to the patient, than telling to the physician.
Rarely, palpation is not even necessary, as the hernia is large enough to be
Direct hernias (because of their acquired nature) tend to occur in older
patients and those that are overweight. Other factors that cause stress on
the lower abdominal muscles can produce a hernia.